Tunnel-kiln



- G. H. BENJAMIN.

TUNNEL KILN.

APPLICATION FILED MAY 23. m9.

Patented Feb. 3, 1920.

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TUNNEL KILN.

APPLICATION EILED MAY 23, 1919.

1,329,745. Patented Feb. 3,1920.

2 SHEETS-SHEET 2.

INVENTOR GEORGE HILLARD BEN AMIN, on NEW YORK, N. Y.

TUNNEL-KILN.

Specification of Letters Patent.

Patented Feb. 3, 1920.

Application filed May 23, 1919. Serial No. 2es,2'92.

To all whom it may concern: 1

Be it known that I, GEORGE HILLARD.

BENJAMIN, a citizen of the United States, residing at New York, in the county and State of New York, have invented certain new and useful Improvements in Tunnel-Kilns, of which the following is a specification.

My invention relates ,to tunnel kilns of the type described in my prior Patent No. 1,295,955 dated March 4, 1919. In that patent, individual heating chambers are arranged longitudinally of the interior of the kiln, and an air passage is arranged back of the heating chambers. In this construction, the heating effects are due first to the heat radiated from the opposed surfaces of the oppositely situated heating chambers and by the airy-passing through the rear fines and heated by conduction from the rear and top surfaces of such combustion chambers.

My present construction, as described in this application, differs from my former construction, in that air fines are provided both. at the front and rear of the combustion chambers, so that the heating effects are due almost entirely to the air passing through said flues and heated by conduction. I say almost entirely, for a very small amount of radiated heat from the combustion chambers is indirectly projected to the goods under treatment, v

In the construction shown in this application, the construction of the chambers and rear flues is the same as in my previous patent, but as before stated, there is anadditional fine in front of such combustion chamher, and further, means are provided to vary the diameter of the front fines, as desired, such means consisting of a series of movable screens, each of whichmay be independently moved from the exterior of the kiln. The movable screens primarily serve to prevent the heat radiated from the opposed walls of the opposite chambers from being projected horizontally directly toward the goods under treatment, and secondarily, form one wall of the front air flue. By varying the position of the screens, the size of the front air flues isincreased or decreased, and the temperature of the air discharged at the top of the fines may be variedas will hereinafter be explained.

Referring to the drawings: Figure 1 is a horizontal section.

'Fi 2 is a vertical cross section taken on the line II-II of Fig. 1.

Fig. 3 is a vertical longitudinal section taken' on the line IIIIII of Fig. 1.

Referring to the drawings: 5 indicates the main chamber,'which may be of any suitable construction. Situated within the kiln on each side, arranged longitudinally in line, are individual heating chambers 6 6*6"6 located at a distance from the side walls and top of the main chamber, so as to form air passage 7 between the chambers and the walls. The chambers 6 are so designed, that the side walls 8 and the inner walls9 of the main chamber will occupy vertical planes.- The top wall 10 of the heating chambers 6, is inclined and is located in plane, parallel to the plane of the roof 11 of the main chamber. A portion of the air passage 7 between the top wall 10 of the heating chambers and the roof 11 of the main chamber, is inclined in an upward direction. The object of this construction is to throw the incoming air against the roof 11 of the main chamber, from which it 1s diverted in a downward direction through the goods 12 under treatment in the main chamber, and out through passages 13 which.

connected through the mixing pipe 15 to agas supply pipe 16 and air supply pipe 17.

The gas transmitted from pipe 16 is under pressure from pump 18 and the air from pump 19.. 20 indicates a pump connected to the interior of the kiln at its induction orifice through an air passage 21, which is in communication with passages 13. The eduction orifice 22 of this pump may be connected, as disclosed in my patent above referred to, to one or both of the air flues in front and back of the combustion chamhers.

I have described an air passage 7 as situated back of the combustion chamber, between the combustion chamber and the wall in front. A second air flue 23 is located between the front wall of the combustion chamber and a movable screen 24. Situated at the mouth of the air flue 7 is a damper 25 and a similar damper 26 at the mouth of flue 23. By manipulating these dampers,

extends upward to the top of the combustion chamber 6. The horizontal portion is arranged to move on a bed 29 formed in the body of the kiln. Movement is edected by means of a screw shaft 30 and a screw threaded hand wheel 81.

Ido not in any wise limit myself to the specific construction of the screens or the means for moving the screens, as illustrated, as both may be modified. The screens 24: are formed of clay bricks or other refractory material. 7

By reference to Fig. 1, it will be seen that the length of a screen corresponds to the length of a combustion chamber, so that the position of each screen governs the diameter of the air fine 23 in front of the particular combustion chamber where it is placed. This will be clear from an examination of Fig. 1, where the diameter of the air flues 23, commencing at the left of the figure, are small, then smaller, then smaller, then larger, etc., corresponding to the length of the kiln. The goods 1:2 under treatment, are mounted on a truck 32 which moves OYGI rails 83 situated within the main chamber.

The general operation of my improved kiln is as follows: Air entering the dues 7 and 23, is highly heated by conduction from the side surfaces of the heating chamber 6, passes upward to the roof, the-n downward through the goods on the truck, thence out of the kiln through the due 21' and pump :20 to be again introduced into the kiln through the fines 7 and 23, if desired. The fines 7 are of fixed diameter, whereas the dues :23 are of variable diameter by reason of the fact that the screens 24L may be moved. When the screens are in the position shown at: the right of Fig. 1, that is, with the di ameter of the flues the largest, the air entering the flue 23 will have a free passage and receive the lowest number of heat units. \Vhen, however, the screen is carried into the position shown in front of the third heating chamber from the left, as in Fig. l,

the diameter of the flue is contracted, the movement of the air through the flue is retarded, and the air picks up the greatest number of heat units. Further, when the screens are in the position shown at the left of Fig. 1, the fewest possible heat units are radiated from the surface of the screen next to the goods, and consequently the goods are protected from the radiated heat derived from the combustion chambers. When, however, the screens are in the position shown in front of the third combustion chamber, from the left, Fig. 1, the radiated heat transmitted to the screens is radiated from the surface of the screens and more radiated heat is tranmitted to the goods. Thus the temperature of the air supplied to the goods, as well as the amount of radiated heat which will reach the goods may be regulated, and at the same time the goods, in a measure, protected from the direct action of the radiated heat set free from the inner walls of the combustion chambers.

In thi specification I have described the use of movable screens interposed between the sources of heat and the goods under treatment. I wish it understood that the sources of heat may be combustion chambers,

such as those disclosed in my prior patent above referred to, or any source of heat, and irrespective of whet-her the source of heat sets free heat from the surface of the combus tion chambers of the general nature of those described in my prior patent and in this application, or from open fires, as in ordinary kiln construction, as I consider any construction which makes use of screens, fixed or movable. between the source of heat and the article treated, as within the intent of my invention.

Having thus described my invention, 1 claim:

1. A tunnel oven of the type described, comprising a main chamber, a plurality of structurally independent heating chambers arranged longitudinally in line on each side of the main chamber, an air flue situated behind each chamber, an air flue situated in front of each chamber, a screen situated in front of each chamber, together with means for moving such screens to and from the chamber in front of which they are individually placed.

'2. A. tunnel oven of the type described, comprising a main chamber, combustion chambers arranged on each side of the main chamber, and movable screens situated in front of the combustion chambers.

3. A tunnel oven of the type described, comprising a main chamber, combustion chambers arranged on each side of the main chamber, air fines of definite diameter situated behind the combustion chambers, and air dues of variable diameter situated in front of the combustion chambers.

+1.. A. tunnel oven of the type-described, comprising a main chamber, a plurality of structuraii y independent heating chambers arranged longitudinally in line on each side of the main chamber, means for movin the goods to be treated through the main c amber, and screens interposed between the heating chambers and the goods.

5. A tunnel oven of the type described, comprisin a main chamber, a plurality of structurally independent heating chambers arranged longitudinally in line on each side of the main chamber, means for movin the goods to be treated through the main 0 amher, and movable screens interposed between the heating chambers and the goods.

Tn testimony whereof, I aflix my signature.

GEORGEQHILLARD BEYJAMIN. 

